1. Field of the Invention
The present invention relates to a cooling structure of a test head for IC tester.
2. Prior Art
A prior art arrangement of a cooling structure of a test head for IC tester will be described with reference to FIG. 12.
In FIG. 12, the cooling structure comprises a hollow pipe 11 disposed at the central portion of the test head, a plurality of printed boards 13 disposed radially around the hollow pipe 11, blowers 14 disposed at four courners of the test head, air ventilators 15 disposed at four courners of the test head and a case 16 housing the test head.
ICs are mouted on each of the printed boards 13. The ICs to be tested are normally placed on the central portion of the test head. The printed boards are disposed radially around the pipe 11 so that the distance between each pin of the ICs to be tested and the ICs mounted on each of the printed boards 13 is shortened and spaced for the same interval.
A main portion of the structure in FIG. 12 will be described with reference to FIG. 13.
Inasmuch as the blower 14 rotates so as to to blow the air outside the case 16, the air is sucked from the upper or the lower side of the tube 11 into the printed board 13 through a ventilation hole 17 of the tube 11 and passes out of the case 16.
When the air passes through the printed board 13, the IC mounted on the printed board is cooled.
The numbers of ICs to be mounted on the printed board have been increased and the printed board per se has been of high integration density recently. However, since the cooling structure in FIG. 12 adopts the air cooled type, the air ventilation is deteriorated and the cooling efficiency is not improved. There has been a case that the use of blower 14 is limited because of the environment problem, i.e. noise, vibration, dust and the like caused by the blower 14. Hence, there has been needed the cooling structure without using the blower 14.